Sink



FIG. 1 is a perspective view of a sink showing my new design;

FIG. 2 is a left-side plan view thereof;

FIG. 3 is a right-side plan view thereof;

FIG. 4 is a front plan view thereof;

FIG. 5 is a rear plan view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view.

The broken lines showing environment is for illustrative purposes only and form no part of the claimed design. 

CLAIM The ornamental design for a sink, as shown and described. 